Local time—Temperature-dependent deformation of a woven composite

Moiré interferometry is utilized to investigate the time-temperature-dependent deformation of a woven composite substrate used in multilayer circuit board applications. Creep tests are performed at temperatures ranging from 27 to 70°C, and the resulting longitudinal and transverse displacement fields are measured via moiré interferometry. Measured displacement fields reveal the influence of fabric architecture on woven composite response. The deformation fields in the plane of the composite for loading along both warp and fill directions consist of a periodic arrangement of high-strain and low-strain regions in accordance to the interlacing bundle architecture. The deformation fields over the cross-section of the composite indicate that neighboring unit cells are subjected to equal and opposite bending moment even when the composite is loaded in uniaxial tension.